1. Field of the Invention
This invention relates to a composite clay material and, more particularly, to the one in which a clay mineral is dispersed in substantially a low polar polymer on the molecular level and a method for producing the composite clay material, as well as a blend material and a composite clay rubber material using the same and production methods thereof.
2. Description of the Related Arts
It has been conventionally studied on adding and kneading a clay mineral to an organic polymer material in order to improve mechanical properties thereof. For example, Japanese Laid-Open Patent Publication No. 74957/1987 or No. 198645/1989 discloses a method for dispersing the clay mineral into thermosetting high polymer such as nylon, vinyl high polymer and epoxy or rubber material. According to the related arts, the following methods are used to disperse the clay mineral; rendering the clay mineral compatible with an organic material by using an organic onium ion to start monomer polymerization between layers of the clay mineral; combining the clay mineral with a growth seed; and inserting a polymerized material between interlayer sections of a clay mineral by kneading them together.
When producing the conventional composite clay material, the clay mineral incompatible with a non-polar polymer hardly accommodates such a non-polar polymer in its interlayer section nor allows its layers expand to accept such a polymer. Therefore it has been difficult to uniformly disperse the clay mineral in the non-polar polymer.
Japanese Laid-Open Patent Publication No. 198645/1989 provides the solution to the aforementioned difficulty. Referring to FIG. 5, an onium ion 960 is incorporated into an end of a chain or a side chain of the polyolefine, the non-polar polymer. The olefin polymer is modified to polymer 96 to render a clay mineral 97 compatible with an organic material.
However incorporation of the onium group into the polyolefine end is chemically difficult in the related art. Additionally since the polyolefine has been inserted into the interlayer section of the clay mineral only at a single stage, the expansion of interlayer distance has not been sufficient in the related art.
In another related art introduced in "Chem. Mater. 5, 1694-1696/1993" written by E. P. Giannelis, et.al., when using polystyrene having no polar group at the main chain or the side chain, only a single layer of polystyrene molecules is allowed to enter between layers, thus the expansion of the interlayer section being limited.